Wound closure product

ABSTRACT

A wound closure system and a method of closing a wound are disclosed. The wound closure system includes a plurality of skin anchors mechanically attached to external skin tissue around a periphery of a wound, a line extending between the skin anchors, the line slidably engaged with each skin anchor, and a biasing member that provides tension on the line to draw all of the skin anchors toward the wound. The method of closing a wound includes the steps of attaching a plurality of skin anchors to external skin around a periphery of a wound, extending a line between the skin anchors around substantially the entire periphery of the wound, and providing tension to the line to draw the skin anchors toward the wound.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/949,115, now U.S. Pat. No. 7,455,681, filed Sep. 13, 2004, whichapplication is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The principles disclosed herein relate generally to wound closure byfacilitating stretching of skin tissue. More specifically, thedisclosure relates to a system and method of facilitating expanding theskin tissue over a wound by use of dynamic force.

BACKGROUND

Surgical procedures such as tumor removal or fasciotomies can result inlarge skin wounds. Chronic wounds such as diabetic ulcers frequently donot heal. Techniques have been developed to facilitate the wound closureof large skin defects and chronic wounds.

Common methods for closure of wounds and skin defects include splitthickness skin grafting, flap closure and gradual closure utilizingtissue expansion. A split thickness skin graft involves removing apartial layer of skin from a donor site, usually an upper leg or thigh,and leaving the dermis at the donor site to re-epithelialize. In thismanner, a viable skin repair patch can be transferred or grafted tocover the wound area. The graft is often meshed, (which involves cuttingthe skin in a series of rows of offset longitudinal interdigitatingcuts) allowing the graft to stretch to cover an area two or three timesgreater than the wound, as well as provide wound drainage while healing.Normal biological function of the skin heals the cuts after the grafthas been accepted. A meshed graft of this type requires a smaller donorarea than a conventional non-meshed or full thickness skin graft. Flapclosure involves transferring skin from an adjacent region to the wound.This technique is only effective in anatomical regions that are amenableto transfer of adjacent skin. It is also a more complex surgicalprocedure involving increased surgical costs and risks. Both of thesemethods do not provide optimal cosmesis or quality of skin cover. Otherdisadvantages of these methods include pain at the donor site, creationof an additional disfiguring wound, and complications associated withincomplete “take” of the graft. In addition, skin grafting oftenrequires immobilization of the limb, which increases the likelihood ofcontractures. The additional operation and prolongation of hospital stayis an additional economic burden.

Gradual, or progressive, closure is another method of wound closure.This technique may involve suturing vessel loops to the wound edge anddrawing them together with large sutures in a fashion similar to lacinga shoe. In addition, the wound edges may be progressively approximatedwith suture or sterile paper tape. The advantages of this gradual, orprogressive, technique are numerous: no donor site is required forharvest of a graft; limb mobility is maintained; superior cosmeticresult, more durable skin coverage, better protection because skin isfull thickness, and maintenance of normal skin sensation may all beachieved.

Existing devices for effecting a gradual closure, however, have manydisadvantages. Current methods and devices rely on static or elasticribbon or suture material which must be repeatedly readjusted in orderto draw wound edges together because a relatively small skin movementsubstantially eliminates much of the closure force. Even with constantreadjustment, maintenance of near constant tension over time isdifficult, if not impossible, to achieve. Since widely used existingclosure techniques involve use of relatively inelastic materials such assutures or surgical tape, a substantial amount of tension is put on thewound edges during periodic adjustment to obtain the necessary closureforce. Excessive tension may cut the skin or cause necrosis due to pointloading of the tissue.

Other approaches use a pulling force across a linear path over thewound. This approach obscures the wound from viewing and must be removedevery two or three days for adjustment and to dress the wound. Multipledevices are required to close most wounds.

What is needed in the art is a gradual wound closure technique that isself-regulating and self-adjusting and uses continuous or dynamictension to draw the wound edges together, without obstructing the woundor needing multiple devices thus eliminating the need for constantreadjustment involved with the static systems.

SUMMARY

The principles disclosed herein relate to wound closure by facilitatingstretching of skin tissue. The disclosure relates to a system and methodof facilitating expanding the skin tissue over a wound by use of dynamicforce.

The disclosure is directed to a wound closure system includingcomponents adapted to apply a dynamic tension force on a plurality ofanchors that are attached to skin tissue surrounding a wound. Thedynamic tension force draws the anchors toward the wound facilitatingstretching of the skin tissue over the wound area.

In one particular aspect, the disclosure is directed to a wound closuresystem comprising a plurality of skin anchors mechanically attached toexternal skin tissue around a periphery of a wound and a line extendingbetween the skin anchors. The line extends around substantially theentire periphery of the wound and application of tension to the linedraws the skin anchors toward each other and toward the wound.

In another particular aspect, the disclosure is directed to a woundclosure system comprising a plurality of skin anchors mechanicallyattached to external skin tissue around a periphery of a wound, a lineextending between the skin anchors, the line slidably engaged with eachskin anchor, and a biasing member that provides tension on the line todraw all of the skin anchors toward each other and toward the wound.

In yet another particular aspect, the disclosure is directed to a methodof closing a wound, the method comprising the steps of attaching aplurality of skin anchors to external skin tissue around a periphery ofa wound, extending a line among the skin anchors around substantiallythe entire periphery of the wound, and providing tension to the line todraw the skin anchors toward each other and toward the wound.

In yet another particular aspect, the disclosure is directed to a woundclosure kit comprising a plurality of skin anchors adapted forattachment to external skin tissue, a line adapted to be slidablyengaged with each skin anchor, and a biasing member adapted to providetension on the line.

In yet another particular aspect, the disclosure is directed to analternative use of the wound closure system where the wound closuresystem may be used for cosmetic purposes to stretch the skin at certainparts of the body that do not include wounds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wound closure system in accordancewith the principles of the present disclosure;

FIG. 2 is an exploded perspective view of a tensioning apparatus of thewound closure system of FIG. 1;

FIG. 3A is a top perspective view of a spool of the tensioning apparatusof FIG. 2;

FIG. 3B is a side elevation view of the spool of FIG. 3A;

FIG. 3C is a bottom perspective view of the spool of FIG. 3A;

FIG. 4 is a top perspective view of a base of the tensioning apparatusof FIG. 2;

FIG. 5 is a top perspective view of a biasing member of the tensioningapparatus of FIG. 2;

FIG. 6A is a top perspective view of a knob of the tensioning apparatusof FIG. 2;

FIG. 6B is a side elevation view of the knob of FIG. 6A;

FIG. 6C is a bottom perspective view of the knob of FIG. 6A;

FIG. 7A is a top perspective view of a cover of the tensioning apparatusof FIG. 2;

FIG. 7B is a bottom perspective view of the cover of FIG. 7A;

FIG. 8A is a top perspective view of a skin anchor suitable for use withthe wound closure system of FIG. 1;

FIG. 8B is a top plan view of the skin anchor of FIG. 8A;

FIG. 8C is a side elevation view of the skin anchor of FIG. 8A;

FIG. 8D is a front view of the skin anchor of FIG. 8A;

FIG. 9 is a top perspective view of an alternative embodiment of a basesuitable for use with the tensioning apparatus of FIG. 2;

FIG. 10A is a top perspective view of an alternative embodiment of acover suitable for use with the tensioning apparatus of FIG. 2;

FIG. 10B is a bottom perspective view of the cover of FIG. 10A;

FIG. 11 is a partial bottom perspective view of the tensioning apparatusof FIG. 2, the tensioning apparatus including the alternative embodimentof the base of FIG. 9, the tensioning apparatus also shown attached to askin anchor including similar features to the skin anchor of FIG. 8A andshown in combination with a tensioning line of the wound closure systemof FIG. 1;

FIG. 12A is a top perspective view of an alternative embodiment of askin anchor suitable for use with the wound closure system of FIG. 1;

FIG. 12B is a top plan view of the skin anchor of FIG. 12A;

FIG. 12C is a side elevation view of the skin anchor of FIG. 12A;

FIG. 12D is a front view of the skin anchor of FIG. 12A;

FIG. 12E is a top plan view of a plate from which the skin anchor ofFIG. 12A is formed;

FIG. 13A is a top perspective view of a third embodiment of a skinanchor suitable for use with the wound closure system of FIG. 1;

FIG. 13B is a top plan view of the skin anchor of FIG. 13A;

FIG. 13C is a side elevation view of the skin anchor of FIG. 13A;

FIG. 13D is a front view of the skin anchor of FIG. 13A;

FIG. 13E is a top plan view of a plate from which the skin anchor ofFIG. 13A is formed;

FIG. 14 is a top perspective view of a fourth embodiment of a skinanchor suitable for use with the wound closure system of FIG. 1;

FIG. 15 is a top perspective view of a fifth embodiment of a skin anchorsuitable for use with the wound closure system of FIG. 1;

FIG. 16 is a top perspective view of a sixth embodiment of a skin anchorsuitable for use with the wound closure system of FIG. 1;

FIG. 17 is a top perspective view of a seventh embodiment of a skinanchor suitable for use with the wound closure system of FIG. 1;

FIG. 18 is a top perspective view of an eighth embodiment of a skinanchor suitable for use with the wound closure system of FIG. 1;

FIG. 19 is a top perspective view of a ninth embodiment of a skin anchorsuitable for use with the wound closure system of FIG. 1;

FIG. 20 is a perspective view of an tenth embodiment of a skin anchorsuitable for use with the wound closure system of FIG. 1, the skinanchor including a hollow barb for oxygen delivery and shown incombination with a tensioning line of the wound closure system of FIG. 1and shown attached to external skin tissue;

FIG. 21 is an exploded perspective view of an alternative embodiment ofa tensioning apparatus suitable for use with the wound closure system ofFIG. 1; and

FIG. 22 is a diagrammatic view of a negative pressure wound dressingapparatus suitable for use with the wound closure system of FIG. 1,shown in combination with a wound closure system including thetensioning apparatus of FIG. 21 and skin anchors with features similarto the skin anchor of FIG. 14.

DETAILED DESCRIPTION

The inventive aspects of the disclosure will now be described byreference to the several drawing figures. The functional features of theinventive aspects can be embodied in any number of specificconfigurations. It will be appreciated, however, that the illustratedembodiments are provided for descriptive purposes and should not be usedto limit the inventions described herein.

A. Wound Closure System

FIG. 1 illustrates one embodiment of a wound closure system 10 havingfeatures that are examples of inventive aspects disclosed herein. Thewound closure system 10 includes a plurality of anchors 20 (individuallyindicated as 20 a, 20 b, 20 c, 20 d, 20 e, and 20 f) positioned aroundthe periphery of a wound 12. Anchors 20 a, 20 b, 20 c, etc. are attachedto the skin surrounding wound 12 by mechanical means (e.g., staples).Anchors 20 a, 20 b, 20 c, etc. are connected to one another by a tensionline 30. Line 30 is movably attached to each anchor 20; typically line30 is slidably attached to anchors 20 so that it can slide relative toeach of the anchors. Although line 30 is illustrated in FIG. 1 as beingattached to anchors 20 a, 20 b, 20 c, etc. so that it extends aroundsubstantially the entire periphery of wound 12, line 30 can also beattached to anchors 20 a, 20 b, 20 c, etc. in a manner as to extendacross the wound 12, i.e., in a “shoe-lace” configuration, although notpreferably. Preferably, however, the tension line 30 is looped to extendaround the periphery of the wound, which leaves the wound accessible forinspections and dressing changes.

The wound closure system 10 may also include a tensioning apparatus 40that is adapted to apply tension to line 30 to draw the anchors 20, andthus the skin, inwardly toward each other and thus over the wound 12.Although depicted as including a separate tensioning apparatus in FIG.1, the wound closure system may instead utilize a line 30 that includeselastic material to provide the dynamic tension on the skin anchors 20.With the use of a tension apparatus 40, however, an inelastic line 30can be utilized to draw the skin anchors 20 toward the wound 12 sincethe tensioning apparatus is adapted to provide the dynamic force neededfor wound closure. An elastic line 30 can also be used in addition to aseparate tensioning apparatus 40.

In a preferred embodiment, tensioning apparatus 40 includes a biasingmember 50 (shown in FIGS. 2 and 5) mounted within the tensioningapparatus 40 to provide the dynamic tension force on the skin anchors20. As the skin stretches and grows over the wound 12, anchors 20 a, 20b, 20 c, etc. move toward each other and toward the wound 12, reducingthe tension on line 30 and creating “slack” on the tension line 30.Biasing member 50 provides tension to take up the slack on the line 30.Although depicted as a coiled spring in FIGS. 2 and 5, the biasingmember 50 may include other structures. The biasing member 50 mayinclude a constant-force spring designed to provide a constant level oftension on the line 30 when it is in a loaded state. The biasing member50 may alternatively include a nonconstant-force spring designed toprovide varying amounts of force on the line 30 depending upon howtightly it is wound. As one skilled in the art will appreciate, theforce application characteristics of such springs depend upon factorssuch as the mechanical properties of the springs.

In certain embodiments, the tension force that is applied to each skinanchor is usually at least 1 oz. and usually no greater than 64 oz.,commonly between 4 and 16 oz.

The tensioning apparatus 40 of the wound closure system 10 can besecured to a patient by surface attachment such as by adhesives, bysuturing, or by other methods as will be discussed in further detailbelow. The tensioning apparatus 40 can also be located at an alternatelocation remote from the patient's body, but preferably is proximate tothe wound area.

The wound closure system 10 can be used to close a wound up to about 10cm in diameter, although it is recognized that this will vary, dependingon circumstances.

B. Tensioning Apparatus

Referring to FIG. 2, an exploded perspective view of the tensioningapparatus 40 of the wound closure system 10 is illustrated therein. Thetensioning apparatus 40 includes a base 60, a cover 70, a spool 80 thatseats on the base 60, the biasing member 50 that is placed around thespool, a linear spring 5 that is inserted into the spool, and a knob 90used to wind the biasing member 50 for application of tension.

Referring to FIGS. 3A-3C, there is generally illustrated the spool 80 ofthe tensioning apparatus 40. The spool 80 includes an upper spring mountportion 82, a lower tension line mount portion 84, and a main plate 86separating the two portions. In this embodiment, all the portions of thespool 80 are depicted as integrally formed from one unitary piece.However, it will be appreciated that in other embodiments, the spool maybe formed from multiple separate pieces that are coupled together.

The upper spring mount portion 82 has a generally cylindrical shape. Theupper mount portion 82 includes a slot 88 adapted to receive one end ofthe biasing member 50 as will be discussed in further detail below. Theupper spring mount portion 82 also includes a well 6 for the placementof the linear spring 5 (seen in FIG. 2), the purpose of which will bediscussed in further detail below. The well 6 is not a throughhole andextends only about halfway down the length of the upper spring mountportion 82. The linear spring 5 is sized such that when the linearspring 5 is placed within the well, a portion of the spring 5 protrudesupwardly out of the well (not shown in the FIGS.).

The lower tension line mount portion 84 defines two winding grooves 85,87. The lower winding groove 87 is defined between two seat plates, alower seat plate 81 and an upper seat plate 83. The upper winding groove85 is defined between the main plate 86 and the upper seat plate 83. Theseat plates 81, 83 provide structure for seating the spool 80 into thebase 60 of the tensioning apparatus. The spool 80 also defines a pair ofholes 89, an upper hole 89 a and a lower hole 89 b, located on twoopposing sides of the spool 80, as best seen in FIG. 3B. Only one pairof the holes 89 is seen in FIG. 3C. The upper holes 89 a are definedwithin the upper winding groove 85 between the main plate 86 and theupper seat plate 83 and the lower holes 89 b are defined within thelower winding groove 87 between the two seat plates 81 and 83. The holes89 a and 89 b are used to couple a length of line 30 to the spool 80.

For example, to couple the line 30 to the spool, a first end of the line30 is threaded through hole 89 a. A knot is tied, the knot being largeenough that the first end of the line 30 will not slip through the hole.The other end of the line 30 is threaded through hole 89 b located inthe lower winding groove 87 and a similar knot is tied. In this manner,the line 30 can be coupled to the spool ready to be wound. The two endsof the line 30 are preferably attached to holes in separate windinggrooves to facilitate winding of the line 30 and keep line 30 untangledduring winding. The ends of the line may be coupled on opposing sides ofthe spool or they may be coupled on the same side of the spool as longas they are kept in separate winding grooves to reduce any kind oftangling of the line 30.

Referring to FIG. 4, there is generally illustrated the base 60 of thetensioning apparatus 40. Base 60 includes a generally circular main bodyportion 61 and an elongated snout portion 62. Disposed around the mainbody 61 are three legs, generally indicated at 63 that may be used tomount the base 60 to exterior skin tissue. Each leg 63 is depicted asincluding a suture hole 64 for suturing the base 60 to skin. Althoughdepicted as being adapted for mounting to the skin by way of suturing,the base need not have the suture holes 64 and can be mounted to skin inother ways such as by adhesives, straps, etc. As discussed previously,the base 60 and hence the entire tensioning apparatus 40 can also belocated at a location outside the patients body if desired, preferablyproximate to the wound area 12.

The base 60 defines an upper mounting portion 69 protruding upwardlyfrom the base. The mounting portion 69 defines an interior cavity 65shaped to receive the lower tension line mount portion 84 of the spool80. The mounting portion 69 of the base 60 also defines two elongateparallel slots 66, 67 running from the front of the snout portion 62 tothe inner cavity 65. The slots 66, 67 are used to seat the tension line30 extending from the spool 80 to the periphery of the wound 12, as willbe discussed in further detail below. Preferably, slots 66 and 67 seatthe two portions of the line 30 coming from different winding grooves ofthe spool. In this manner, the two portions of the line 30 are keptentirely separated by the slots 66 and 67, although uniform tension isprovided on both ends of the line by the spool 80. By keeping the twoends of the line 30 separate with the two slots 66 and 67, the line 30can also be unwound in an easier manner during initial set-up andreadjustment phases, without the possibility of the line gettingtangled. It is possible, though not preferable, to have a single slot,or even no definite structure for maintaining line 30.

The snout portion 62 of the base is provided with an elongate shape sothat the portions of the tension line 30 coming out of the base 60 canbe in line with the skin anchors 20 located around the periphery of thewound 12, as seen in FIG. 1. In this manner, an even distribution ofpulling force can be kept on the skin around wound 12 since the tensionline 30 keeps a shape corresponding to the periphery of the wound, whichis generally a circular shape. Depending on the shape of the wound, thesnout portion 62 of the base 60 can be placed at various positionsdepending on where the force is desired to be concentrated. By providingstructural support for the line 30, the snout portion 62 can also allowthe tensioning apparatus 40 to be positioned at a remote location fromthe wound 12. Remote placement of the tensioning apparatus 40 makes iteasier to inspect and dress the wound 12.

Referring to FIG. 5, there is generally illustrated therein the biasingmember 50 of the tensioning apparatus 40. The biasing member 50 isdepicted as a spring essentially formed from a coiled-up metal band 51.As discussed previously, the spring can be a constant force spring thatprovides a constant level of tension regardless of how tight it is woundor it can be a nonconstant-force spring that provides different levelsof tension at different degrees of tightening. In a preferredembodiment, the band 51 is made of type 301 high-yield stainless steel.In certain embodiments, the biasing member 50 can provide a load forceof about 4 lbs. As will be appreciated in the art, the load force of thebiasing member 50 can vary depending on certain properties such as thethickness, the diameter, or the material of the band 51.

The band 51 defines an inner end 52 and an outer tab portion 53. Thecoiled up band 51 is positioned around the upper spring mount portion 82of the spool 80. When positioned as such, the inner end 52 of the band50 is placed within the slot 88 defined on the upper spring mount 82 ofthe spool 80. The outer tab 53 of the band 51 cooperates with the knob90 of the tensioning apparatus 40 for winding purposes. Winding of thebiasing member 50 will be described in detail further below.

Referring to FIGS. 6A-6C, there is generally illustrated the knob 90 ofthe tensioning apparatus 40 that is used to load and unload the biasingmember 50. The knob 90 includes a generally cylindrical body 91 with anexterior surface 92 and an interior cavity 93 defined by an interiorsurface 94. The interior cavity 93 is shaped and sized to tightlyreceive the biasing member 50. The interior surface 94 includes radiallyarranged vertical indents 95 that cooperate with the outer tab 53 of thebiasing member 50 to wind the biasing member, as will be discussed infurther detail below. The interior surface also includes a slot 7adapted to receive a portion of the linear spring 5 (seen in FIG. 2)that protrudes out of the upper spring mount portion 82 of the spool 80.

The exterior surface 92 of the knob 90 defines radially arrangedgripping features 96 to facilitate turning the knob during winding. Thegripping features 96 are depicted as vertical grooves but may be otherstructures adapted to facilitate the winding process of the biasingmember 50.

The exterior surface 92 of the knob 90 also includes horizontal tabs 97arranged radially around the circumference of the knob. The tabs 97include ramped surfaces 98 that ramp upwardly to a land area in acounterclockwise direction. The tabs 97 are spaced and definerectangular gaps 99 thereinbetween. The tabs 97 cooperate with the cover70 of the tensioning apparatus 40 to wind the biasing member 50, to lockthe biasing member 50 when it is loaded, and to release the biasingmember 50 when desired, as will be described below in further detail.

Referring to FIGS. 7A-7B, there is generally illustrated therein thecover 70 of the tensioning apparatus 40. The cover 70 generally includesan interior shape configured to fit on exterior of the base 60. Thecover includes a main body portion 71 and an elongate snout portion 72.The main body portion 71 fits over the main body portion 61 of the base60 and the snout portion 72 fits over the snout portion 62 of the base60. The cover 70 includes an inner wall 75 that is shaped and sized tosnugly fit over the mounting portion 69 of the base 60.

As seen in the bottom perspective view of the cover 70 in FIG. 7B, theinner wall 75 of the cover 70 defines a flange 73 surrounding the innerperimeter of the main body portion 71. The flange 73 is adapted to trapthe horizontal side tabs 97 of the knob 90 to capture the knob 90 inbetween the base 60 and the cover 70 of the tensioning apparatus 40. Theflange 73 defines radially arranged rectangular tabs 74 that are adaptedto slide over the ramped surfaces 98 of the horizontal tabs 97 of theknob 90 and fit into the rectangular gaps 99 defined between thehorizontal tabs 97 as the knob is turned clockwise, as will be describedin further detail below. The cover 70 may be coupled to the base 60 byvarious methods including friction fit, by adhesives, by fasteners, by asnap fit, etc.

The tensioning apparatus 40 can either be located near the wound area 12or away from the wound area 12. In certain embodiments, the tensioningapparatus can be secured to the patient by methods such as by suturing,by adhesive, adhesive tape, a bandage, or wound dressing. In otherembodiments, the tensioning apparatus can be located away from apatient's body.

C. Skin Anchors

As seen in FIG. 1, a plurality of anchors 20 a, 20 b, 20 c, etc. areplaced around the periphery of the wound 12. Each anchor 20 ismechanically fastened to the skin, such as by conventional medical skinstaples 22. Suturing can also be used to mechanically attach the anchors20 to the skin.

Referring to FIGS. 8A-8D, the anchor 20 includes a first end 21, asecond opposite end 23, and a generally rectangular body 24 definedbetween the first end 21 and the second end 23. The anchor 20 includestwo skin-penetrating barbs 25 proximate the first end 21 for securementto the skin. The barbs 25 preferably have a bearing surface with a largeenough width perpendicular to the direction of the tension so that thebarbs 25 do not cut through the skin when pulled toward the wound intension. In this manner, as the barbs 25 move in toward the wound, theskin moves with the barbs. The barbs 25 can be bent at an angle A_(B)less than about 90 degrees from the skin surface. The barbs 25 can bebent, preferably, at about a 60 degree angle A_(B) to improve theirability to hold into the skin. The edges of the barbs 25 are sharp tomake it easy to penetrate the skin upon insertion. Two pairs ofindentations, generally indicated at 26 are formed on the body 24 of theanchors to help guide where mechanical attachment, such as staples 22,are to be placed. Two pairs of tabs 27 extending out from the opposingsides of the body 24 are adapted to abut against the staples 22 to pullthe skin toward the wound 12. Although the guiding indentations 26 arelocated forward of the tabs 27, as the anchors 20 are pulled in towardthe wound 12, the tabs 27 eventually abut against the staples 22 afterinitial stretching of the skin around the wound area is achieved.

A tension line tab 28 defines a tension line slot 29 formed at the firstend 21 of the anchor 20 for receiving the tension line 30. The tensionline slot 29 is formed with a wide lead-in area to make it easy toreceive the tension line 30. The tension line slot 29 is sized such thatthe tension line 30 is “snapped-in” past the narrowest point of the slot29 to prevent the line from accidentally being pulled out.

Anchor 20 includes a length L_(A). The barbs 25 include a penetrationdepth D_(P). The inner edges of the barbs 25 are spaced apart a distanceof W_(B). The dimensions, L_(A), D_(P), W_(B), and A_(B) can be variedaccording to desired skin anchor performance in different parts of thehuman body and for different types and ages of skin.

Table 1, below, illustrates two example configurations for the anchor,with two different sets of dimensions that are suitable for use with thewound closure system 10. Anchors with example configuration 1 arepreferably retained by two conventional regular size medical skinstaples (5.7 mm×3.9 mm). Anchors with example configuration 2 arepreferably retained by two wide size medical skin staples (6.9 mm×3.9mm).

TABLE 1 Anchors (unless otherwise specified, all dimensions are ininches) L_(A) D_(P) W_(B) A_(B) Configuration 1 0.739 0.158 0.186 60°Configuration 2 0.607 0.115 0.206 60°

In a preferred embodiment, the anchor 20 is formed from stainless steelsheet such as 302 or 316 containing 8 to 14% nickel content. It will beappreciated that the anchors can be stamped with a progressive die, wireEDM-cut, shaped from metal, shaped from wire, injection molded, or madeby other suitable methods. The anchors can also be manufactured fromother metals such as titanium.

D. Tension Line

Referring to FIG. 1, the tension line 30 of the wound closure system 10is illustrated as being coupled to the anchors 20 around the peripheryof the wound 12. The tension line 30 may be a nylon or polypropyleneline, suture material, string, a cable, a wire, or other similar item.Line 30 should be sufficiently flexible and bendable to allow slidableattachment to anchors 20. In a preferred embodiment, the tension line 30is conventional suture material. One preferred line 30 is made fromnylon and has a tensile strength of about 6 lbs to 10 lbs. The tensionline 30 preferably includes a thread diameter of about 0.5 mm to 0.6 mm.

Although depicted as including a separate tensioning apparatus in FIG.1, the wound closure system 10 may instead utilize a line 30 thatincludes elastic material to provide the dynamic tension on the skinanchors 20. With the use of a tension apparatus 40, however, aninelastic line 30 can be utilized to draw the skin anchors 20 toward thewound 12 since the tensioning apparatus is adapted to provide thedynamic force needed for wound closure. An elastic line 30 can also beused in addition to a separate tensioning apparatus 40.

E. General use of Wound System

In general use, first, the skin anchors 20 are placed at generally equalintervals around the periphery of the wound 12. The skin engagementbarbs 25 of the skin anchors 20 are then pressed into the skin. Eachskin anchor 20 may then be coupled to the skin with the use of, forexample, staples 22. The two pairs of indentations 26 defined on thebody 24 of the skin anchors 20 serve as target areas for placement ofthe staples 22.

After the line 30 has been attached to the spool 80 through the holes 89a and 89 b and wound around the upper and lower winding grooves 85, 87,the tensioning mechanism is assembled with the spool 80 fitting into thebase 60. After winding of the line 30, the loop of line 30 is guided outof the snout portion 62 of the base 60 with the two sides of the line 30being seated into the parallel slots 66, 67 of the base. The biasingmember 50 is placed on top of the spool 80, the knob 90 is placed on topof the biasing member 50 after the linear spring 5 is placed within thewell 6 of the spool 80, and the cover 70 is mounted on top of the base60 trapping the knob 90 thereinbetween the base 60 and the cover 70.

After assembly, the loop of line 30 from the tensioning apparatus 40 ispulled out until there is enough line to fit over the tension line tabs28 of the skin anchors 20. After line 30 is placed over all the skinanchors 20, the knob 90 of the tensioning apparatus 40 is turnedclockwise. The turning of the knob 90 pulls the line 30 in and starts towind the biasing member 50 located therewithin.

Rotating the knob 90 clockwise causes the rectangular tabs 74 on theinside of the cover 70 to ride up and over the ramped surfaces 98 of thehorizontal tabs 97 of the knob 90. The linear spring 5 protruding out ofthe spool 80 is used to exert an upward force on the knob 90 to keep thehorizontal tabs 97 of the knob 90 pressed against the flange 73 of thecover 70. A clicking sound may be heard as the rectangular tabs 74 areseated into the rectangular gaps 99 as they ride up and over the rampedsurfaces 98. The interlocking of the rectangular tabs 74 within therectangular gaps 99 prevents the knob 90 from turning backwards in acounterclockwise direction.

When the knob 90 is turned clockwise, the biasing member 50 is loadedbecause the outer tab portion 53 of the coiled band 51 fits into one ofthe vertical indents 95 causing the biasing member 50 to turn with theknob 90. When the coiled band 51 is initially in an unwound orientation,the large diameter of the band 51 creates a tight fit with the interiorof the knob 90 creating a substantial amount of friction with theinterior of the knob 90. In this manner, the outer tab portion 53 iskept pressed against the inner surface 94 of the knob 90, within one ofthe vertical indents 95. As the biasing member 50 is wound, it becomessmaller and eventually obtains a diameter small enough that the outertab 53 no longer exerts enough friction force against the interiorsurface 94 of the knob 90. At this point, further winding of the knob 90causes the outer tab portion 53 to slip out of the vertical indents 95.This slipping gives an indication that the biasing member 50 is fullywound.

Since the spool 80 is connected to the biasing member 50, turning of theknob 90 also causes turning of the spool 80, tightening the line 30around the anchors 20. The biasing member 50 is wound to such extentthat it applies a dynamic force on the line 30 pulling the skin anchors20 in toward the wound 12. The design of the snout 62 of the base 60makes it possible to concentrate all the pulling force into one area.The snout 62 also inhibits any pulling on the tensioning apparatus 40because the tip of the snout 62 aligns the tensioning apparatus 40 withthe loop of line 30 around the periphery of the wound 12 diverting allthe tension forces to a transverse direction along the loop instead ofin the direction of the snout 62 itself. As the anchors 20 move intoward the wound 12 by the stretching of the skin, the wound-up biasingmember and hence the spool 80 keeps the line 30 taut.

Occasionally it may be necessary to release the line 30 to reposition itfor adjustments or to remove the tensioning apparatus 40. Pushing downon the knob 90 causes the linear spring 5 (see FIG. 2) to compress andthe rectangular tabs 74 on the inside of the cover 70 to disengage fromthe rectangular gaps 99 defined around the knob 90. This causes the knob90 to be able to be turned backwards in the counterclockwise directionand the line 30 to come out.

F. Alternative Embodiments

1) Base of Tensioning Apparatus

An alternative embodiment of a base 160 suitable for use with thetensioning apparatus 40 of FIG. 2 is illustrated in FIG. 9. The base 160is similar to the base 60 of FIG. 4 except that base 160 includescertain additional features to those of the base 60.

First, base 160 includes fastener holes 168 adjacent the suture holes164 defined on the three legs 163 disposed around the main body 161. Thefastener holes 168 are configured to cooperate with the fastener holes176 located in an alternative embodiment of the cover 170 that isdepicted in FIGS. 10A and 10B.

Second, the base 160 includes an additional cavity 165 defined in theupper mounting portion 169 of the base 160. The cavity 165 may be usedoptionally to fixedly couple one end of the line 30 to the base 160instead of winding both ends of the line 30 around the spool 80. Afterone end of the line 30 has been tied in a knot large enough so that itwon't slip out of the cavity 165, that end can be placed into the cavity165. In this manner, the biasing member provides tension on all theanchors 20 by pulling on only one end of the line 30 since the other endis fixedly supported by the base 160.

Third, the base 160 is provided with an extended snout portion 162wherein the front of the snout 162 includes a ramped surface 166. Theramped surface 166 is configured to cooperate with the tension line tab28 of a skin anchor 20 to fixedly mount the base 160 to a skin anchor.The ramped surface 166 is inserted within the tension line slot 29defined by the tension line tab 28 of the skin anchor 20 as the tensionline tab 28 abuts against the front of the snout 162. With this feature,the base 160 can be mounted onto an anchor 20 as seen in FIG. 11 and thetensioning apparatus can be allowed to move with the anchor 20 as theskin is stretched toward the wound 12. As illustrated in FIG. 11, sincethe snout portion 162 of the base 160 can be placed above the anchor 20and can serve the function of an anchor, this embodiment of the baseallows anchors 20 to be pulled in closer approximation to each otherwithout the snout 162 taking up any space between the anchors 20. Thebase 160 is held coupled to the anchor 20 because the tension providedon the line 30 keeps the front of the snout 162 abutting against thetension line tab 28 of the skin anchor.

As illustrated in the bottom perspective view in FIG. 1, the bottom sideof the base 160 may also include an indentation 167 configured toaccommodate the thickness of a staple 22 mounted on top of the body 24of an anchor 20.

2) Cover of Tensioning Apparatus

An alternative embodiment of a cover 170 suitable for use with thetensioning apparatus 40 of FIG. 2 is illustrated in FIGS. 10A and 10B.The cover 170 is similar to the cover 70 of FIGS. 7A and 7B except thatcover 170 includes fastener holes 176 defined around the perimeter ofthe cover. The fastener holes 176 are adapted to cooperate with thefastener holes 168 of the base 160 of FIG. 9 to couple the cover 170 tothe base 160 by means of fasteners (not shown in the FIGS.).

3) Skin Anchors

An alternative embodiment of an anchor 120 suitable for use with thewound closure system 10 of FIG. 1 is illustrated in FIGS. 12A-12E. In apreferred embodiment, the anchor 120 is formed from stainless steel suchas 302 or 316 containing 8 to 14% nickel content. It can also be madefrom titanium. The stamped sheet 122 from which the anchor 120 is formedis illustrated in FIG. 12E in an unformed configuration.

The anchor 120 includes a first end 121 and a second end 123 and agenerally rectangular body 124 defined between the first end 121 and thesecond end 123. The anchor 120 includes two skin-penetrating barbs 125proximate the first end 121 for securement to the skin. The barbs 125are flat on the bearing surface that pulls the skin closer over thewound. They are also bent at about a 60-degree angle to improve theirability to hold into the skin. The edges of the barbs 125 are sharpenedto make it easy to penetrate the skin upon insertion. Two tabs 127 areformed on the body 124 to help guide where mechanical attachment, suchas staples 22, are to be placed. A tension line tab 128 defines atension line slot 129 formed at the first end 121 of the anchor 120 forreceiving the tension line 30. The tension line tab 128 is formed with awider lead-in to make it easy to receive the tension line 30 and thenprevent the line from accidentally pulling out.

Anchor 120 includes dimensions A, B, C, D, E, F, G, H, I, J, K, L, M, N,O, P, Q, R, S, T, and U as seen in FIGS. 12C and 12E. The dimensions(A-U) can be varied according to desired skin anchor performance indifferent parts of the human body and for different types and ages ofskin.

Table 2, below, illustrates three example configurations for the anchor120, with three different sets of dimensions (A-U) that are suitable foruse with the wound closure system 10. An anchor with exampleconfiguration 1 is preferably retained by two conventional regular sizemedical staples (5.7 mm×3.9 mm). Anchors with example configurations 2and 3 are preferably retained by two wide size medical staples (6.9mm×3.9 mm).

TABLE 2 Two-Barbed Anchors (unless otherwise specified, all dimensionsare in inches) A B C D E F G H I J K Configuration 1 0.551 0.305 0.1080.055 0.016 0.078 0.017 60° 0.197 0.727 0.197 Configuration 2 0.6300.325 0.108 0.065 0.016 0.119 0.017 60° 0.236 0.806 0.217 Configuration3 0.709 0.344 0.108 0.065 0.016 0.158 0.017 60° 0.236 0.885 0.236 L M NO P Q R S T U Configuration 1 0.049 0.197 0.098 0.010 0.104 0.010 0.0300.030 0.030 0.039 Configuration 2 0.081 0.256 0.118 0.010 0.104 0.0100.030 0.030 0.030 0.049 Configuration 3 0.115 0.315 0.138 0.010 0.1040.010 0.030 0.030 0.030 0.049

Another alternative embodiment of an anchor 220 is illustrated in FIGS.13A-13E. The anchor 220 is also preferably formed from stainless steelsuch as 302 or 316 containing 8 to 14% nickel content. It can also bemade from titanium. The stamped sheet 222 from which the anchor 220 isformed is illustrated in FIG. 13E. The anchor 220 is essentially similarto the anchor 120 except that the anchor 220 includes fourskin-penetrating barbs 225 and one staple tab 227. Two of the barbs 225a are located proximate the first end 221 of the anchor 220 and twobarbs 225 b are located approximately halfway between the first end 221and the second end 223 of the anchor 220. The tab 227 for guiding wherethe staples 22 are to be placed is formed adjacent the second end 223 ofthe anchor 220. Similar to anchor 120, a tension line tab 228 defines atension line slot 229 formed at the first end 221 of the anchor 220 forreceiving the tension line 30.

Anchor 220 includes dimensions A′, B′, C′, D′, E′, F′, G′, H′, I′, J′,K′, L′, M′, N, O′, P′, Q′, R′, and S′ as seen in FIGS. 13C and 13E. Asfor anchor 120, these dimensions (A′-S′) can vary depending on thedesired skin anchor performance in different parts of the human body andfor different types and ages of skin.

Table 3, below, illustrates three example configurations for the anchor220, with three different sets of dimensions (A′-S′) that are suitablefor use with the wound closure system 10. An anchor with exampleconfiguration 1 is preferably retained by one conventional regular sizemedical staple (5.7 mm×3.9 mm). Anchors with example configurations 2and 3 are preferably retained by one wide size medical staple (6.9mm×3.9 mm).

TABLE 3 Four-Barbed Anchors (unless otherwise specified, all dimensionsare in inches) A′ B′ C′ D′ E′ F′ G′ H′ I′ J′ Configuration 1 0.551 0.1060.160 0.075 0.016 0.077 0.017 60° 0.197 0.727 Configuration 2 0.6300.106 0.199 0.075 0.016 0.118 0.017 60° 0.236 0.806 Configuration 30.709 0.106 0.258 0.075 0.016 0.157 0.017 60° 0.236 0.885 K′ L′ M′ N′ O′P′ Q′ R′ S′ Configuration 1 0.098 0.394 0.098 0.010 0.030 0.030 0.0300.010 0.034 Configuration 2 0.098 0.472 0.118 0.010 0.030 0.030 0.0300.010 0.039 Configuration 3 0.098 0.571 0.138 0.010 0.030 0.030 0.0300.010 0.049

FIGS. 14-19 illustrate six other embodiments of skin anchors 320-820,respectively, suitable for use with the wound closure system 10.

The skin anchor 320 of FIG. 14 includes a rectangular body 324 includinga first end 321 and a second end 323. The body 324 includes two slots327 for placement of staples 22, one located proximate the second end323 and the other located between the two ends 321 and 323. The body 324also defines a slot 329 adjacent the first end 321 for slidableplacement of the tension line 30. Anchor 320 shown in FIG. 14 may bemade of molded plastic.

The skin anchors 420 and 520 illustrated in FIGS. 15 and 16,respectively, are adapted to receive the tension line 30 from theunderside of the body of the anchors prior to the anchors being attachedto the skin. Anchors 620, 720, and 820 illustrated in FIGS. 17-19,respectively, include tension line tabs similar to anchors 20-220 andare adapted to receive the tension line 30 from the upper side of thebody. Anchors 420-820, as illustrated in FIGS. 15-19, can be made invarious ways such as from a plate, such as the plate 122 of FIG. 12E or222 of FIG. 13E, from wire, by injection molding, or other suitablemethods.

Referring to FIG. 20, another embodiment of a skin anchor 920 suitablefor use with the wound closure system 10 is illustrated. Skin anchor 920is shown in combination with the tensioning line 30 of the wound closuresystem 10 and shown attached to external skin tissue with staples 22.The skin anchor 920 is essentially similar to skin anchor 320 of FIG. 14except that skin anchor 920 includes a barb 925 that is hollow. Theanchor 920 includes a through hole 915 defined in the body 924 that runsthrough the hollow barb 925. The barb 925 also includes an exit hole 916adapted to be exposed to the undersurface of the skin once the barb 925penetrates the skin. The through hole 915 may be connected to an oxygensupply wherein oxygen is fed into the hollow barb 925 and out of theexit hole 916. In this manner, oxygen can be supplied around the woundarea 12 through skin punctures that has been created by such skinanchors 920. It is known in the art that stretching of the skin tends todisrupt oxygen flow around the wound area. Exposing oxygen to a woundspeeds up the healing and reduces the chance of infection by actingdirectly on anaerobic bacteria, enhancing leukocyte and macrophageactivity and increasing the effects of antibiotics. The oxygen would beinfused into the wound on a periodic basis to optimize wound healing andprevent over saturation with oxygen.

It will be understood that skin anchor 920 is only one exampleembodiment of an anchor that can be used to supply oxygen to the woundarea. In certain embodiments, the body of the skin anchor might notinclude a throughhole and the oxygen supply can be directly linked to anentry hole on the barb of the skin anchor without the oxygen firstpassing through the body of the skin anchor. In such embodiments, thebarb would include an entry hole exposed above the skin for attachmentto an oxygen line and an exit hole disposed underneath the skin.

Although the anchors depicted in the figures are illustrated to have agenerally rectangular body, it will be appreciated that other bodyshapes are also possible. A rectangular body may be utilized toaccommodate the shape of conventional staples. The body of each anchorincludes a longitudinal axis extending from the first end to the secondend. The body of each anchor is preferably symmetrical about thelongitudinal axis to equalize or improve pressure on the staples, thebarbs or on any other method of attachment utilized for securement toskin.

4) Tensioning Apparatus

Referring to FIG. 21, an exploded perspective view of an alternativeembodiment of a tensioning apparatus 240 suitable for use with the woundclosure system 10 of FIG. 1 is illustrated therein. The tensioningapparatus 240 includes features similar to the tensioning apparatus 40depicted in FIG. 1, however, operating in substantially a differentmanner in principle.

The tensioning apparatus 240 includes a housing 290 that is formed froma base 260 and a top cover 270. The housing 290 encloses a biasingmember 250 and a spool member 280. Biasing member 250 provides thedynamic force for line 30, and spool member 280 collects and retains theportion of line 30 not being used.

The base 260 includes a generally circular interior cavity 265 forreceiving the biasing member 250 and the spool member 280. The interiorcavity 265 is defined by a bottom inner surface 268 and a surroundingperiphery edge 269. An extended member 267 protrudes from the center ofthe bottom inner surface 268. The extended member 267 defines a slit 264used for attachment of the biasing member 250, as will be describedfurther below.

The top cover 270 is placed on top of the base 260 to securely enclosethe biasing member 250 and the spool member 280 within the housing 290.In the embodiment of the tensioning apparatus 240, illustrated in FIG.21, the periphery edge 269 and the top cover 270 define intermatingthreads 263 and 274, respectively, for removably coupling the top cover270 to the base 260. It will be appreciated that other means ofattachment between the top cover and the base are possible, such as snapfitting, friction fitting, twist-locking, etc. An exit port 262 isdefined in the periphery edge 269 of the base 260.

The biasing member 250 is positioned within the interior cavity 265 ofthe base 260. The biasing member 250, as in the biasing member 50 ofFIG. 1, is essentially formed from a coiled-up metal band 251. In apreferred embodiment, the band 251 is made of type 301 hi-yieldstainless steel. In certain embodiments, the biasing member can providea load force of about 4 lbs. In other embodiments, the amount of pullingforce on the tension can be changed by changing the diameter of thetension line take up spool.

The band 251 defines an inner tab portion 252 and an outer tab portion253. The biasing member 250 is positioned around the protruding extendedmember 267 of the base 260, so that inner tab portion 252 is receivedwithin the slit 264 to couple the biasing member to the base 260.

The spool member 280 is placed around the biasing member 250 within thebase interior cavity 265. The spool member 280 defines a slit 288. Theouter tab portion 253 is placed within the slit 288 to couple thebiasing member 250 to the spool member 280.

With this configuration, when the spool member 280 is turned, thebiasing member 250 is compressed or loaded. In the embodiment of thetensioning apparatus 240 illustrated in FIG. 21, turning the spoolmember 280 clockwise loads the biasing member 250 and turning itcounterclockwise unloads the biasing member 250. It will be appreciatedthat, in other embodiments, an opposite orientation may be used.

The tension line 30 (shown in FIG. 1, but not in FIG. 21) is initiallywound around the spool member 280 to set up the system. The tension line30 is wound in such a manner as to not slip relative to the spool member280 when pulled from an unwound end.

After the tension line 30 is wound around the spool member 280, pullingon the tension line 30 turns the spool member 280, which, in turn, loadsthe biasing member 250. The portion of the tension line 30 that will beattached to the anchors exits out of the exit port 262 of the housing290.

A force guide tube 261, serving a similar function to the snout portion62 of the base 60 of FIG. 4, positioned between tensioning apparatus 240and the wound 12, provides a conduit through which line 30 passes. Aforce guide tube such as the one illustrated in FIG. 21 may also be usedin the bases 60 and 160 of FIGS. 4 and 9, respectively, addition to theelongated snout portions of the bases 60 and 160. By providingstructural support for the line 30, the force guide tube 261 allows thetensioning apparatus 240 to be positioned at a remote location from thewound 12. Remote placement of the tensioning apparatus 240 makes iteasier to inspect and dress the wound 12. The force guide tube 261 alsoprovides a way to concentrate the pulling forces into a single pointrather than multiple points on the tensioning apparatus 240. The forceguide tube 261 is depicted as coupled to the base 260 through the exitport 262. The force guide tube 261 may be coupled to the exit port 262in various ways such as friction fitting, threading, adhesives, etc.

The force guide tube 261 is sized to have various lengths according towound location and patient needs. In certain embodiments, the forceguide tube may be integrally coupled to the tensioning apparatus or maybe a removable part of the tensioning apparatus.

In a preferred embodiment, the tensioning apparatus 240 may also includea tension drag mechanism (not shown in the FIGS.). The tension dragmechanism may be an integral part of the base 260. The tension dragmechanism may include a drag knob that can be activated to stop orreduce the pulling force of the biasing member 250. In one embodiment,the tension drag mechanism may include an on/off type mechanism. In suchan embodiment, pressing the drag knob applies enough friction on thebiasing member 250 to cause it to stop pulling. In a preferredembodiment, the tension drag mechanism is constructed to apply varyingdegrees of drag or friction on the biasing member 250. In this way, thetension drag knob can be activated to stop the pulling force and, then,released gradually to allow the biasing member 250 to apply tensiongradually. Gradual release prevents the biasing member 250 from applyingfull tension immediately after being released, which can be painful forthe patient.

The tension drag mechanism can be used when first setting up the woundclosure system 10 around the wound 12 or during readjustment of thesystem. In use of the tension drag mechanism, the tension line 30 can bepulled from the tensioning apparatus 240 and the tension drag knob canbe activated to temporarily stop the pulling force of the biasing member250. When the tension line 30 is placed around the anchors, the tensiondrag knob can be released to allow biasing member 250 to start applyinga tension force again.

The tensioning apparatus 240 can either be located near the wound area12 or away from the wound area 12 if a force guide tube 261 is used. Incertain embodiments, the tensioning apparatus 240 can be secured to thepatient by surface attachment, such as by adhesive, adhesive tape, abandage, or wound dressing. In other embodiments, the tensioningapparatus can be located outside of a patient's body.

5) Alternative Use of Wound Closure System

The wound closure system may be used to stretch the skin for purposesother than for wound closure. One such example use of the wound closuresystem is directed to improving the cosmetic effects of male-patternbaldness. For example, the skin anchors may be placed on the human scalparound the periphery of the so called “bald-spot.” The tensioningapparatus or an elastic tension line, for example, then, may be used togradually draw the skin anchors inwardly to stretch the skin with thehair follicles surrounding the bald-spot to eventually reduce the sizeof the bald-spot.

G. Negative Pressure Wound Dressing Apparatus

Referring to FIG. 22, there is illustrated therein a diagrammatic viewof a negative pressure wound dressing apparatus 100 adapted to be usedin conjunction with the wound closure system 10. Although depicted asbeing used in combination with a wound closure system that includes thealternative embodiment of the tensioning apparatus of FIG. 21 and skinanchors with features similar to the skin anchor 320 of FIG. 14, thenegative pressure wound dressing apparatus 100 may also be used with thewound closure system 10 depicted in FIG. 1.

The negative pressure wound dressing apparatus 100 includes a filter pad101 that is adapted to be placed in or over the wound 12. A drain tube102 extends from the filter pad 101 to a pressure vessel such as squeezebulb 103. The squeeze bulb 103 includes an interior volume for holdingliquids. The squeeze bulb 103 also includes a drain cap 104 that isremovably coupled to the squeeze bulb 103 for emptying the bulb. It willbe appreciated that the drain cap 104 can be coupled the squeeze bulb103 in a number of different ways such as with threads, by snap-fitting,etc.

In general use, the filter pad 101 is placed in the wound 12. Thesqueeze bulb 103 is squeezed by the user to create a negative pressurein the filter pad 101. The negative pressure then soaks up any excessfluid there may be in the wound area 12 and helps pull the wound closed.As the squeeze bulb 103 is filled with excess drainage from the woundarea 12, it can be emptied through the drain cap 104. Preferably, thesqueeze bulb 103 is squeezed two or three times a day by the user. Inother embodiments, the negative pressure wound dressing apparatus 100may be constructed such that the squeeze bulb 103 is compressedautomatically. For example, the squeeze bulb 103 may be attached to aperson's body in such a manner as to be compressed each time the personbreathes. In other embodiments, the squeeze bulb 103 may be squeezedautomatically by other bodily movements such as the movement of aperson's leg or arm. Body movement might also be used in conjunctionwith piezo-electric materials to generate power to operate the negativepressure mechanism.

As shown in FIG. 22, a cover 105 that covers the entire wound area 12and the skin anchors 320, may be placed on the skin so that suctionthrough the filter pad 101 is more effective by creating an internalvacuum around the wound area 12. Preferably, the cover 105 isimpermeable to liquid and to air. Plastic is a suitable material forcover 105. The cover 105 may be attached to the skin around theperimeter of the wound 12 by adhesives or other suitable methods.

From the foregoing detailed description, it will be evident thatmodifications and variations can be made in the devices of the inventionwithout departing from the spirit or scope of the invention. Therefore,it is intended that all modifications and variations not departing fromthe spirit of the invention come within the scope of the claims andtheir equivalents.

1. A wound closure system comprising: (a) a plurality of skin anchorsadapted to be attached to external skin tissue around a periphery of awound; (b) a line adapted to extend between the skin anchors and aroundsubstantially the entire periphery of the wound without any portion theline penetrating through the skin tissue; (c) a biasing member that isseparate from the line that is adapted to apply a continuous pullingforce on the line to draw all of the skin anchors toward each other,wherein no portion of the biasing member is located inside the peripheryof the wound when the wound closure system is set up, the biasing memberadapted to apply a continuous pulling force on the line to keep the linetaut between the skin anchors when the skin anchors move toward eachother, wherein the biasing member includes a spring; and (d) a housingthat houses the spring, the housing including a spool rotatably coupledto the housing, the spool coupled to the spring and adapted for windingthe spring for the application of the continuous pulling force on theline, the housing and the spring including intermating structuresadapted for winding the spring, wherein the intermating structures areadapted to slip with respect to each other when the spring has beenfully wound to provide an indication that the spring is fully wound. 2.A wound closure system according to claim 1, wherein at least one of theanchors is adapted to be attached to external skin tissue with askin-penetrating structure.
 3. A wound closure system according to claim1, wherein the plurality of skin anchors includes at least three or moreskin anchors.
 4. A wound closure system according to claim 1, whereinthe intermating structures include radially arranged indents formedwithin the housing and a radially outwardly protruding tab of thespring.
 5. A wound closure system comprising: (a) a plurality of skinanchors adapted to be attached to external skin tissue around aperiphery of a wound; (b) a line adapted to extend between each of theskin anchors without any portion the line penetrating through the skintissue; (c) a biasing member that is separate from the line that isadapted to apply a continuous pulling force on the line to draw all ofthe skin anchors toward each other, wherein no portion of the biasingmember is located inside the periphery of the wound when the woundclosure system is set up, the biasing member adapted to apply acontinuous pulling force on the line to keep the line taut between theskin anchors when the skin anchors move toward each other, wherein thebiasing member includes a spring; and (d) a housing that houses thespring, the housing including a spool rotatably coupled to the housing,the spool coupled to the spring and adapted for winding the spring forthe application of the continuous pulling force on the line, the housingand the spring including intermating structures adapted for winding thespring, wherein the intermating structures are adapted to slip withrespect to each other when the spring has been fully wound to provide anindication that the spring is fully wound.
 6. A wound closure systemaccording to claim 5, wherein the line is adapted to extend aroundsubstantially the entire periphery of the wound.
 7. A wound closuresystem according to claim 5, wherein at least one of the anchors isadapted to be attached to external skin tissue with a skin-penetratingstructure.
 8. A wound closure system according to claim 5, wherein theplurality of skin anchors includes at least three or more skin anchors.9. A wound closure system according to claim 5, wherein the intermatingstructures include radially arranged indents formed within the housingand a radially outwardly protruding tab of the spring.
 10. A woundclosure system according to claim 5, wherein the line is adapted toslidably engage each of the skin anchors.
 11. A wound closure systemcomprising: (a) a plurality of skin anchors adapted to be attached toexternal skin tissue around a periphery of a wound; (b) a line adaptedto extend between each of the skin anchors without any portion the linepenetrating through the skin tissue, the line adapted to extend betweenthe skin anchors in a shoe-lace configuration wherein the line includesa portion that is adapted to cross the wound at least twice when thewound closure system is set up; (c) a biasing member that is separatefrom the line that is adapted to apply a continuous pulling force on theline to draw all of the skin anchors toward each other, wherein noportion of the biasing member is located inside the periphery of thewound when the wound closure system is set up, the biasing memberadapted to apply a continuous pulling force on the line to keep the linetaut between the skin anchors when the skin anchors move toward eachother, wherein the biasing member includes a spring; and (d) a housingthat houses the spring, the housing including a spool rotatably coupledto the housing, the spool coupled to the spring and adapted for windingthe spring for the application of the continuous pulling force on theline, the housing and the spring including intermating structuresadapted for winding the spring, wherein the intermating structures areadapted to slip with respect to each other when the spring has beenfully wound to provide an indication that the spring is fully wound. 12.A wound closure system according to claim 11, wherein at least one ofthe anchors is adapted to be attached to external skin tissue with askin-penetrating structure.
 13. A wound closure system according toclaim 11, wherein the plurality of skin anchors includes at least threeor more skin anchors.
 14. A wound closure system according to claim 11,wherein the intermating structures include radially arranged indentsformed within the housing and a radially outwardly protruding tab of thespring.
 15. A wound closure system according to claim 11, wherein theline is adapted to slidably engage each of the skin anchors.